OBJECTIVE: To extract the polysaccharide from Phyllanthus emblica L. and analyse its effect of cleaning oxygen radical. METHOD: A technic was found to extract Phyllanthus emblica L. polysaccharide (PePS). Hot water extraction, ethanol sedimentation, tonnic acid deproteinization and H₂O₂decolourization were performed. Tests were also done with the extraction material, including the determination of sugar and protien content, the analysis of polysaccharide behaviour, and the determination of the activities of cleaning oxygen radical. RESULTS: The extraction ratio was 1.94%. With Sephadex G-100 chromatography, the elution peak of the PePS was single sugar peak and also single protein peak. Its total sugar content was 64.5%. Its protein content was 35.0%. IR showed that the absorption peak of sugar and protein. DSC revealed that a super peak of absorption heat at 117.20 ℃ and three low peaks of absorption heat and one low peak of release heat. In the determination of the avtivities of cleaning hydroxid radical, its IC₅₀ was 638μg. In the determination of the activities of cleaning superoxide anion radical, its IC₅₀ was 500μg. In the determination of inhibiting lipid peroxidation, its IC₅₀ was 1.25mg. CONCLUSION: PePS is a kind of proteoglycans. It has the effect of cleaning oxygen radical. Its activities and amounts are relative.